Frequencies for first 10,000 rows of prescr7 variable in nhamcsopd2007 dataset :

            for rx7, |
 prescription status |
                code |      Freq.     Percent        Cum.
---------------------+-----------------------------------
   prescription drug |        967        9.67        9.67
nonprescription drug |        127        1.27       10.94
        undetermined |         47        0.47       11.41
             illicit |          1        0.01       11.42
                   . |      8,858       88.58      100.00
---------------------+-----------------------------------
               Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016